1. Field of the Invention
The present invention relates to a black photosensitive resin composition colored black, and to a color filter and a method of producing the same.
2. Description of the Related Art
CCD, CMOS or the like solid-state image sensors have a light-shielding film for noise prevention and image quality enhancement. For forming the light-shielding film, for example, widely used is a photosensitive resin composition containing a black colorant such as carbon black or titanium black.
For the photosensitive resin composition for use in forming a light-shielding film (black pattern) for solid-state image sensors, desired is a black resist capable of sufficiently blocking the incidence of visible light. In order that a resist material could have sufficient light-shieldability, the content of the colorant of light-shielding material must be increased or the film thickness must be increased. As a result, the optical density of the film itself shall increase, and when the film is patterned through exposure to a light source of, for example, i-line or the like, the light could not reach the depth of the film and therefore the film could not be fully photocured. In such a case, the depth of the film may undergo overdevelopment and the pattern may be thereby thinned; and the adhesiveness of the pattern formed on a wafer by the subsequent development may be poor and the pattern may be peeled away from the wafer. In addition, the film surface layer could hardly be cured sufficiently, and surface layer defects may occur on the side surfaces of the pattern.
Relative to such phenomena, JP-A-2002-088136 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”) and JP A-2006-259716 disclose black photosensitive resin compositions comprising a compound having a specific skeleton, which, however, are still unsatisfactory for satisfying all the requirements of good stability (free from sensitivity change and patterning profile change with time), high light-shieldability and good adhesiveness to substrate of the black photosensitive resin compositions and the requirement of the absence of surface layer defects on the side surfaces of the formed patterns.